From af92a645d30b9ac775cdfe5dd56ea1d66fb6e492 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= Date: Wed, 13 Jul 2016 17:44:03 +0200 Subject: pack-objects: do not truncate result in-pack object size on 32-bit systems MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit A typical diff will not show what's going on and you need to see full functions. The core code is like this, at the end of of write_one() e->idx.offset = *offset; size = write_object(f, e, *offset); if (!size) { e->idx.offset = recursing; return WRITE_ONE_BREAK; } written_list[nr_written++] = &e->idx; /* make sure off_t is sufficiently large not to wrap */ if (signed_add_overflows(*offset, size)) die("pack too large for current definition of off_t"); *offset += size; Here we can see that the in-pack object size is returned by write_object (or indirectly by write_reuse_object). And it's used to calculate object offsets, which end up in the pack index file, generated at the end. If "size" overflows (on 32-bit sytems, unsigned long is 32-bit while off_t can be 64-bit), we got wrong offsets and produce incorrect .idx file, which may make it look like the .pack file is corrupted. Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano --- builtin/pack-objects.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c index a3a98c574..ac7a3a589 100644 --- a/builtin/pack-objects.c +++ b/builtin/pack-objects.c @@ -341,8 +341,8 @@ static unsigned long write_no_reuse_object(struct sha1file *f, struct object_ent } /* Return 0 if we will bust the pack-size limit */ -static unsigned long write_reuse_object(struct sha1file *f, struct object_entry *entry, - unsigned long limit, int usable_delta) +static off_t write_reuse_object(struct sha1file *f, struct object_entry *entry, + unsigned long limit, int usable_delta) { struct packed_git *p = entry->in_pack; struct pack_window *w_curs = NULL; @@ -415,11 +415,12 @@ static unsigned long write_reuse_object(struct sha1file *f, struct object_entry } /* Return 0 if we will bust the pack-size limit */ -static unsigned long write_object(struct sha1file *f, - struct object_entry *entry, - off_t write_offset) +static off_t write_object(struct sha1file *f, + struct object_entry *entry, + off_t write_offset) { - unsigned long limit, len; + unsigned long limit; + off_t len; int usable_delta, to_reuse; if (!pack_to_stdout) @@ -491,7 +492,7 @@ static enum write_one_status write_one(struct sha1file *f, struct object_entry *e, off_t *offset) { - unsigned long size; + off_t size; int recursing; /* -- cgit v1.2.1